Mycobacterium tuberculosis has been infecting humans for several millennia and in a substantial number of cases--some two billion, in fact--the bacteria isn't active at all. Instead, it hides inside cell aggregates, latent and persistent, waiting to break out. Now, scientists from the Florida campus of The Scripps Research Institute (TSRI) have discovered several first-in-class compounds that target these hidden infections by attacking a critical process the bacteria use to survive in the hostile environment of the lungs. These compounds also show excellent activity against multidrug resistant (MDR) and extensively drug-resistant (XDR) strains, in addition to the standard laboratory reference strain, H37Rv, of M. tuberculosis.